This is a shared instrumentation request to replace an ailing 22-year old instrument with state-of-the-art capabilities. The high, highly active Core Group faculty have projects covering: calcium binding proteins which fold via the molten globule; preparation and utilization of various myoglobin and carbonic anhydrase mutants and forms to be probed by electron spin resonance methods for intramolecular distance measurements in solution; kinetics and mechanism of folding of a variety of proteins, enzymes and their mutants; and detailed investigations of denatured state energetics. There is a strong institutional emphasis on research as reflected by a 20% cost-sharing commitment and guarantees of maintenance and operating costs throughout the period of this project and beyond. This is a relatively small funding request to the NIH which will certainly be 'value-added' in the ability to generate new and important research from both the NIH funded grantees as well as other user groups generating meaningful results for planning future NIH, federal and other funded research programs. Lastly, as additional 'value- added,' the involvement of collaborative NIH supported researchers at the University of Colorado Health Sciences Center underscores the shared nature of this instrumentation that reaches out beyond the sponsoring institution.